AWS Step Functions
Developer Guide


All work in your state machine is done by tasks. A task performs work by using an activity or an AWS Lambda function, or by passing parameters to the API actions of other services.

AWS Step Functions can invoke Lambda functions directly from a task state. A Lambda function is a cloud-native task that runs on AWS Lambda. You can write Lambda functions in a variety of programming languages, using the AWS Management Console or by uploading code to Lambda. For more information see Creating a Lambda State Machine.

Step Functions can coordinate some AWS services directly from a task state. For more information see Service Integrations.

An activity consists of program code that waits for an operator to perform an action or to provide input. You can host activities on Amazon EC2, on Amazon ECS, or even on mobile devices. Activities poll Step Functions using the GetActivityTask and SendTaskSuccess, SendTaskFailure, and SendTaskHeartbeat API actions.

The Amazon States Language represents tasks by setting a state's type to Task and by providing the task with the Amazon Resource Name (ARN) of the activity or Lambda function.

For more information about specifying task types, see Task in Amazon States Language.

For examples of how different kinds of tasks are used, see the Tutorials section.